It is widely recognised that successful online systems are not those that simply fulfil some functional specifications, but rather systems that are developed to also meet a number of non-functional requirements such as security, reliability and trust. It is also generally accepted that the development of quality online systems is not anymore just the task of single individuals or mono-cultural teams but it often involves diverse and disperse teams with members from different cultures and backgrounds. Some non-functional requirements (such as security or reliability) enjoy a general consensus, independent of the cultural background of the developers. Unfortunately, this is not the case for trust, despite the growing interest in trustworthy information systems. The very nature of trust indicates that it is understood differently by different individuals and relates to personal experiences more than other non-functional requirements. In this paper we identify the field of study to support the inclusion of considerations regarding trust in the design of online systems, to provide the understanding and support that is in par with security or reliability.